Gas-operated self-ejecting and self-loading firearm



GAS OPERATED SELF-EJECTING AND SELF-LOADING FIREARM 15 Sheets-Sheet l H.W. HESTER Filed May l2, 1948 M 2 l|\l\l|| r@ n, m l t TVQ@ ,wlw WM 3 wwm e r P07 M S 2 m mw m f F I m v M H F L S M E H m w m ma uw man 3N @u#Trl H. J@ F s m @u n sw mw 11 m illl HU l www o o s m mm. @Nmwwv MM M lL w m. 3m www QQ 5, w M x l W m .N M i uw F H. W. HESTER GAS OPERATEDSELF-EJECTING AND SELF-LOADING FIREARM Filed May 12, 1948 15Sheets-Sheet 3 WS cmu Sv wm. ww am mw QQ H. w. HEsTER 2,637,247

GAS OPERATED sELF-EJECTING AND SELF-LOADING FIREARM 13 Sheets-Sheet 4May 5, 1953 Filed May 12, 1948 H. W. HESTER May 5, 1953 GAS OPERATEDSELF-EJECTING AND SELF-LOADING FIREARM Filed'May 12. 1948 l5Sheets-Sheet 5 H. W. H ESTER May 5, 1953 GAS OPERATED SELF-EJECTING ANDSELF-LOADING FIREARM Filed May l2, 1948 13 Sheets-Sheet 6.

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H. W. HESTER May 5, 1953 GAS OPERATED SELF-EJECTING AND SELF-LOADINGFIREARM Filed May 12. 1948 s LT May 5, 1953 H. W. VIY-HVESTER Y* GASOPERATED SELF-EJECTING AND SELF-LOADING FIREARM Filed May 12, 1948 l5Sheets-Sheet 8 fa@ Wfes .BY

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May 5, 1953 H. w. HEsTER 2,637,247

GAS OPERATED SELF-EJECTING AND SELF-LOADING FIREARM Filed May 12, 194815 Sheets-Sheet 9 fnvenor Haz@ Pl/.Heserf May 5, 1953 H. w. HEsTER2,637,247

GAS OPERATED sELF-EJECTING AND SELF-LOADING FIREARM Filed May 12, `1948l5 Sheets-Sheet lO ay 5, 1953 H. w. HESTER 2,637,247

GAS OPERATED SELF-EJECTING AND SELF-LOADING FIREARM Filed May 12, 194813 Sheets-Sheet l1 H. W. HESTER May 5, 1953 GAS OPERATF) SELF-EJECTINGlAND SELF-LOADING FIREARM Filed May l2, 1948 13 Sheets-Sheet 13 Patenteday 5, 1953 GAS-OPERATED SELF-EJECTNG AND SELF-LOADING FIREARMApplication May 12, 1948, Serial No. 26,623

18 Claims.

The present invention relates to self-ejecting and self-loading rearms,and may be embodied in pistols, rifles, or shotguns, Which may besemiautomatic or fully automatic, but is exemplied herein in asemi-automatic rifle suitable for military use.

The semi-automatic rifles of the prior art with which I am familiar arenot certain in their operation under all conditions, for the reason thatsuch guns, which operate by recoil, develop a diierent amount of force,depending upon the condition of the primer and the amount of charge ineach shell. Such guns as have their ejecting and loading mechanism, inthe prior art, operated by gas from the explosion, are subject to thesame defect, that the amount of force depends on the strength of thecharge and the condition of the primer.

Guns of the prior art which transmit the force of the gas of theexplosion to springs are subject to the same defect, that the amount offorce may be insuincient or excessive; and an insucient amount of forcemay cause the gun to fail to eject or fail to load, whereas an excessiveamount of force may break the parts or subject the gun parts toexcessive strains and Wear.

Another of the objects of the present invention is the provision of animproved self-ejecting and self-loading firearm, which is adapted tooperate certainly and smoothly independent of the strength or Weaknessof the charge or the condition of the primer, for the reason that thepresent rearm is adapted to utilize the explosive force of the gas untila spring has been com pressed only to a certain predetermined desiredamount, thereafter releasing all of the gas immediately. Thus thecharacteristics of the piston and spring may be made such that thespringis always compressed sufficiently to operate the ejecting andloading mechanism, but no more energy than desired can be impressed uponthe spring because the rest of the gas is immediately and completelyreleased when the spring receives its desired tension.

Another object of the invention is the provision of an improvedself-rejecting and self-loading firearm oi the class described, in Whichthe gas acts forwardly toward the muzzle when discharged is dischargedin the same direction as the muzzle so that there is no backwarddischarge of gas toward the user, nor any necessity for close tting orpacked piston rods which might become fouled or corroded by discharginggases.

Another object of the invention is the provision of an improved firearmconstruction of the class described, which is so constructed that thebarrel can be cleaned from the breach Where it should be cleaned,because cleaning from the muzzle tends to Wear the riing by means of thecleaning rod, whereas the riing is already slightly tapered at thebreech.

A further object of the invention is the provision of an improved gunconstruction in which the breech is fully enclosed and cannot be openedby mishandling, such as a jar on the butt of the gun, and in which thebreech is normally locked shut against firing when there are no shellsin the magazine or breach, and is normally unlocked and in firingcondition except for the safety when the gun is loaded.

Another object is the provision of an improved gun construction of theclass described, which operates smoothly and certainly and will not failto eject and reload When the gun is held loosely in the hand at the sideof the user Without resisting recoil, and will not fail to eject andreload Whether it is pointed up or down or in any other direction.

Another object of the invention is the provision of an improved gunmechanism, all of the parts of which are suitably enclosed andprotected, which is light in Weight and lighter than similar guns of theprior art, which is simple in construction, sturdy, which has a minimumnumber of parts and less parts than the guns of the prior art whichperform similar functions, which has no loose pins and which may be usedfor a long period of time Without necessity for repair or replacement ofits parts.

Still a further object of the invention is the provision of an improvedtrigger mechanism, which is more sensitive yet perfectly sate, and whichcomprises a spring and toggle arrangement with the parts located pastdead-center when the trigger is cocked so that the trigger need only belifted past dead-center to trip it, the amount of force to lift it is aminimum and both the amount of force and the amount of movement of thetrigger may be adjusted by adjusting the points of pivot of one of thetoggle levers.

Another object of the invention is the provision of an improved securingdevice for securing the forepart of the barrel to the stock, including ametal band which surrounds the barrel and has a notch to engage a parton the barrel to prevent turning, and a suitable Wedging hook engaging aplate on the lower side of the stock to assure a tight mounting and toarrange the parts so that the recoil Will tend to tighten the mounting.

Another object of the invention is the provision of an improvedmechanism for securing the breech of the barrel to the stock, whichincludes trunnions for pivotal movement of the breech on the stock, anda toggle link for pivots which pass dead-center to assure a tightmounting of the breech against a mounting plate having a large area fortransmittingethe. foi-cesen reeoilcto the.v stock, andjfasuitabletanlr`which is'securelyemii bedded and anchored in the stock.

Another object is the provision of an improvedt.

trigger guard which guards the trigger only Where it is necessary, andprovides greater ffreedomiol'fvv action to the user, and the provisionoanrim' proved breech block mechanism, the...ipart ofrwhich is pivotallymounted .ori-.therearzpart se that the forepart may be moveddowmrrardlt-intev locking engagement in front of locking lugs xedlymounted with respect to thebu'rel'.y

Another object is the provision of an improvedv gun mechanism whichoperates moreV smoothly, with. freer action, and` less friction, andlesswear on; the .parts than, the; devices" of theprior' art,v and.which mayv lie manufacturedat vvalowercost;

than the .deyicesoftlieprior' art which. are corrf n structedl for the.same. purpose.'

Another object oitheinventionis the provision?A of an impitovedbree'chb1ock"an'd' receiver con;- str-uction, in. whichn theA block operateswith a minimum, amount oli "friction orso-'arranging the` block. that'ritA moves continuously: fromi tl'i-'ev open. to the locked.- position'Without a Stegand turning motiom as in the" prior art; and* Withoutrubbing .thel face.ofj` the. block againstthe car'-Vv trid'ge. nonr,ubbingj.thelocking.lugs against' the-` Referringtotlia drawings; ofwhich there are thirteen sheets accompanying-the spe'ciiieation';

Fig. 1 .isafragmentary side elevationa'llvieyv onthefassembledlgimshowing` the stoclendof the. glllf Eig; lciisa simil'anview.cttlieimddleportion i oi thegun, continuingjmm the ,right'vendvofFigure, 1;,

Eig., lois., a similar.: view; of 'theremaining end portion of.' the..gun. beginningV at' the right' of` Figure la Vand;lextleodillg;tiothemuzzle' Fig.. 21 aitragment'ary, topplan; view 'of' one* end`portionofthe gun beginningjwith thestock Eig... 2a, is v a, similar, .View of:the middlev portion' of the gun continuing from theright' endj of Figure2";

Fig. 2o is a similar View of the'remainingendA portion ofi the` guncontinuingfrom".tleri'glfit` end off Figure 2a;P

Figi.. 3i is ai fragmentarybottom plan view' ofA` theA endfportion of'the'gun which' beginsrwith the stock;

Fig,` Sajisasimil'ar view.' ofthe middle portion of' the' guncontinuing; from the right'endi ofy Figure 3;

Fig.' Bb" is asimilar viewof the' remaining end portion; of the gunextending Yto thef muzzle and* continuing from tlierightY end` ofIiigureftt;`

Fig; 4 isa'vertical sectional View taken on^-a plane passing-throughthe-axis of the-stock, withparts'I of1 the stoclrand' housing broken'away to showI the' positionof the parts when the# gun is` closed and themagazine is insertedV with thev hammercocked- Fig. 5 is a fragmentarytop plan view of the loading mechanism shown apart from the receiver,with the parts in the position that the loading rod catch has, whenengaging the action rod;

Fig. 6 is a similar View, with the parts in the positionA their assumeatterri tl'iewactonv.r rod has moved to the;v right'sumciently tocausethe loading rod to move a shell into position to be engaged ythebreech, and the action rod has now become disengaged from the catch ofthe loading rod;

Figi."isziaifragmentary vertical axial sectional View ofthe-part oi themechanism of both the breech,hloclsY and mechanism, in the posi-...tionzffwhich they assume after the shell has been inserted into;theyba-rrel;

Fig. 8. is a vertical sectional View taken on the plane-o'thelinelooking in the direction oftheiar-.rows

Fig. 9 is a vertical sectional view taken on the planeof thev lineQ--Sci Figure 7lookingin the direction' ofthe' arrows and omittingithev.breeech bl'ocli4 andvoth'er detail's'which are infront ofi this' planeto.' emphasize; the'. illustration o1"`V the. triggerV Amechanisrnr YFig? l0' isa Viewsimilanto Figure 7,' showing" theparts in the positionwhich they assume after' the' li'ammerhas been released andjs in contactwith the firing' pin ;j

11 isla fragmentary view'similar to; Figuren, 10iy ,omitting the iiring;mechanism but. showing thebreech block; being `returned' to. itsvopenpnsi'- tion, and now' located at: the point' Where the; emptyshellisbelng; ejected;

I2" is`a' vieu/'similar toFigur l0', .with tire 4 breech block" open,showing aV fragment, of, the magannelledpwith shells., with the loadingrod' in position'to push one'shell' out of.tlie'magazine; into position.to` bepengagedbythe blocks,

Eig; 13is" a" view similar to Figure .12,.with the breech block and,loading rod in the position which' theyassurne when theblock.is.closing,vl and ashell has already` been movedjupi into positiontojbe engagedby the breechpblock which will drive Fig; 14 is a'.fragmentary.` side'y elevational viewy oi the, receiver;` breech endlofA the barrel, and operating'rod; showingtheioperating. rod in theforward' position .with Vthe actionloclewhich secures. it thereWhentthere are' no ,shells in the magazine;

Fig; 15; is afragmentary bottom planvi'ew'of' the mechanism of Figure',la, showingithe operating rodengagingthe loadinggrod catch ;I

Fig. 16 is a transverse sectional View taken on the/plane of 'thelinei-iofFigure 14, looking in the, direction of the arrows, showing' thepivot for the action' lock; v

Fig; y17 is a transverse sectional View taken on tlieplane of` the linellt-ll of Figure14, looking inthe direction of the arrowsand showingtheupwardly projecting actuating member, bymeans'- of which the actionlock is manually released;

Fig; lA is an transverse sectional View takenl oir the plane of the lineiii-i8 of Figure-14, lookingA in the direction of thearrows; `showingthe lockingy arrangements of theaction loch;

Fig.' 1'9 isfa transverse sectional view takenA on the plane of the linelil-l-S-of Figure 14', showing additional details ofthe action lock;

Fig: 201s -a bottom plan View of the receiver,` showing a shell in theact of` being inserted in theV barrel by the breech,p the loading rodhaving completed its function;

Fig; 2l' is-y an exploded- View' in` perspectiva showing all of theparts which are associated with the main spring and its housing, bymeans of which the breech is automatically opened and closed, andlatched in either position;

Fig. 22 is an exploded view in perspective, showing all of the parts ofthe firing mechanism;

Fig. 23 is an exploded View in perspective, showing all of the parts ofthe breech block, including the extractor and ring pin;

Fig. 24 is a side elevational view in partial section on a verticalplane passing through the axis of the barrel, showing the details of themode of actual mounting of the barrel on the front end of the stock andthe details of the main spring, cylinder and piston, by means of whichthe main spring is given its operating compression;

Fig. 25 is a transverse sectional view taken on the plane of the line25-25 of Figure 24 on an enlarged scale;

Fig. 26 is another transverse sectional view taken on the plane of theline 26-25 of Figure 24, looking in the direction of the arrows;

Fig. 27 is a similar View taken on the plane of the line 2'i-2l ofFigure 24, looking in the direction of the arrows;

Fig. 28 is a similar view taken on the plane of the line 28-28 of Figure24, looking in the direction of the arrows;

Fig. 29 is a fragmentary side elevational view which represents acontinuation of the right end of Figure 14, showing the barrel whenremoved from the stock, with the main spring housing and retractorspring;

Fig. 30 is a bottom view of the mechanism of Figure 29, and represents acontinuation extending from the right of Figure l5;

Fig. 3l is a fragmentary side elevational view of the barrel removedfrom the stock, showing the same mechanism as Figure 24, with the pistonin its extreme right position at the moment when all of the excess gasis being instantaneously discharged in a forward direction;

Fig. 32 is a side elevational view, with the barrel tilted relative tothe stock and the toggle link placed in proper position to effect itssecurement when the barrel is pivoted downward to the position of Figure4;

Fig. 33 is a view in perspective of the toggle link, by means of whichthe breech of the barrel is secured to the stock;

Fig. 34 is a top plan View of that part of the receiver |84 whichcooperates with the toggle link |36 in securing the rear end of thebarrel to the stock; and

Fig. is a fragmentary side elevational view showing how the lugs on thebreech block move down in front of the shoulders on the receiver, andlugs on the breech block cover move forwardly over those of the block tolock them in this position when the block is closed.

Referring to Figure l, 49 indicates in its entirety the gun assembly,which includes the stock 4l, barrel assembly 42, breech block assembly43 and magazine 44, these being the main parts visible in this figure.

The stock may have its rearward portion of any suitable shape, but ispreferably formed behind the trigger 45, with a. pistol grip portion 4Eand forwardly of the trigger, with a substantially flat lower surface 4lthat is adapted to support a metal plate 48 serving both as a triggerguard and a magazine guide.

The lower part of the stock at the pistol grip 46 is preferably formedwith a concave rounded lower surface 49, providing sufficient spacebehind the trigger for the remaining three fingers of the hand to gripthe pistol grip 46, and providing additional space in front of thetrigger 45 to receive the trigger finger even when covered with a glove,with the nger out of contact with the trigger.

As the trigger 45 cannot be actuated by forces applied to its rear side5i), it is guarded only at its lower end or point 5I and curved frontside 52 by the trigger guard plate 48. This plate is shown at the rightend of Figure 3, and it comprises an elongated steel plate which taperstoward its rear end portion 53, which serves as the trigged guard.

The tapered trigger guard portion 53 extends backwardly of the fiatsurface 41 of the stock, Figure 1, sufficiently to extend under thepoint 5| of the trigger and to guard the front of the trigger. The restof the trigger guard plate 48 is shown in Figure 3a, and it will benoted that it is provided with a pair of apertures for wood screws 54that are driven into the bottom of the stock.

At its forward end the plate 48 is also tapered and rounded, and it isprovided with a magazine aperture 55 which is substantially rectangularbut has a circular forward end 56 corresponding substantially to theshape of the magazine housing, the magazine being shown in place inFigure 3a and indicated by the number 44.

Referring to Figure 4, the lower flat surface lll of the stock isprovided with a shallow rectangular groove 53, which is adapted toprovide guiding surfaces for a magazine latch 59. The magazine latch ismerely a flat strip of steel, the forward edge 6U of which is like ablunt knife edge for engaging in a complementary groove 6l in themagazine housing 44 to retain the maga.- zine in the gun assembly.

The magazine latch plate 59 is held in its groove 53 by the triggerplate 48 which permits it to slide, and the stock preferably has a bore62 for housing a spring 53. The spring 53 has one end 54 held in acomplementary bore in the stock, and its other end 65 caught in a holein upwardly extending tang 65 on the latch plate 59.

Between its ends spring 63 preferably has a safety-pin loop El', and theends of the spring are urged apart urging the latch plate 5S! toward theright in Figure 4. The latch plate 5S is also formed with an outwardlyand upwardly curved finger piece 68, Figure la, which is housed in acurved recess B9 in the stock 4i so that the latch plate 5S may be movedbackward against the spring 53 to withdraw its latching edge 50 from thegroove 6l of the magazine housing 44. This permits the magazine to bewithdrawn from its recess. The stock is also formed with an oval recess'i5 corresponding in shape substantially to the opening 55 in the plate48 for receiving and guiding the magazine and holding it in properposition.

The magazine The magazine 44 is shown in bottom plan in Figure 3a, inside elevation and partial section in Figure 4. The magazine 44 includesa housing il which may be formed of a plate of steel that is bent tosubstantially U-shape, having two ila-t side walls and the curved endwall 1). The free ends of this plate are joined by a flat end wall 'i3which may be soldered or welded to them providing a housing which isopen at the top and bottom.

7 Atftheiebnttomthisdiousirrg has :two rpairsfzof inwardly :turned-retaining flanges v.lTigu-re Bra, whichfengage fa.'removabla'lriottomwall .1l-5, Figure 4. The removable bottom-wall .ltcomprises a metal:strip Lof :substantially rectangular form roundedlat its vrightencl,i|3lignre 53d, .and yadapted to be received inside the housing 'H,betweenits walls:above.thelretainingganges .At its left cnd,.lFigure.4, .cbottomyplatelle has. an upwardly extending flug ld, kwith lapartially .cylindrical recess 'Tl' .on its right side.

This recess 'il :receives "one of the :partially cylindrical formations78 inthe spring '5.9, which :may be formed yof substantially -IVI-shape. Thus the spring "iii has three such cylindrical formations18,316, ti, and it :has .a--lower leg `82 that engages -the 'bottomplate l5. fits upper `leg is preferably fixedly `secured ,to the topplate 'Sil by 'being slid endwiseinto-suitable slotsin the downwardlyprojecting lugs d5, lwhile the cylindrioalbend Areacts against apartially cylindrical groove on .an angle bracket The topof the magazinehousing has*inwardly turned curved iianges 8B, Figure 1., near the rearwall for ,engaging the shell and holding the .shells .in the magazine.For-wardly of these curved flanges .Elli there are two upwardlyprojecting straight 'flanges 39, and there vis anvcpen space or 4groove:9d between the flanges Bil rand 89 .through `which the rim of a shellmay pass after it has been pushed forwardly out from under the -iiangest8.

. .Rearwardly .of the .retaining flanges there is .an opening .9|exposing the rear of the `upper shell but leaving enough of the rearwall 'i3 .to hold the shell. The loading rodaote through this aperturedi. Thus the rtop wall `of the magazine is secured to thespr-ing .and.constantly Yurged upward bythe reacticm ofthe spring against 4the lowerwall.

The barrel und 'receiver assembly The present semi-automatic mechanismil ay be embodied in pistols, riiies or shutguns, but the embodimentselected to illustrate the invention is an .automatic rie.

I'll'ie barrel Lillie, therefore, .anfelongated tubularrnetal memberofvsteel, which Ais provided with the riled bore .Q2 the .open Amuzzleend of the bore being indicated yat Adjacent its muzzle end the .barrel6.12 carries asuitablesightebead or ridge Sifwhich may be ofany-suitable construction and forms no part of -theinvention FlgureZd.

Adjacent the breech end of the barrel, the barrel carries a suitablesight-base 9E (Figure 2c) comp-rising a larger sleeve. The riiled boreill? (Figure '12) terminates at the breech of the gun in an enlargementlic forming va shell chamber, the enlargement 96 being joined tothe borel2 by a tapered` portion 0l corresponding to the shape of a shellhousing. lll/hen 'the shell has its housingy 98 (Figure l0) with itstapered portion 99 engaging the tapered shoulder Bl in the barrel, theshell has its rim Iilil and annular groove Ii exposed in afrusto-conical recess |82 at the rear .end `of the barrel that is thebreech, 'so that it may be grasped by the extractor.

The bullet may be indicated by the numeral m3. The 'barrel is secured atits rear end to a frame for supporting the gun mechanism, called thereceiver IEM, and for this` purpose the rear end `of the barrel maybethreaded at -I and threaded intoa bore i-ili .in the receiver against an.annular shoulder it?.

The receiver is shownin bottom plan in Figure 20,-insside. elevaticnin.Eigurela in bottom plan in`r'.'igure.l5,inside -elevation .as .to itsinner vwall inigures 7 and .110., insection in Figures '8 ands and alsoin'isecticn-inFigure 12.

Referring to. Figure 420, the receiver comprises a ipa-ir ofsubstantially parallel rearwardly ,extending wa-lls itt land I (l5),Ajoined by the front wall lili kwhich has the bore Iil into which thebarrel is threaded. Looking at the bottom side of thereceiveig there visan enlarged rectangular aperture Iliadjacent the breech recess |82. Thebottom Asurfaces H2 of the two side walls |98, m9 may be Vplane, and theside walls Hit, m9 arejcined intermediate ltheir-ends by an integraltransversely extending bridge H3, vFigure 9.

This vbridge H3 .is substantiallyrectangular in cross-section, but isreduced in thickness at its central portion lift, Figure 9, :thusproviding :Side shoulders .-I I5 which keep the firing mechanismcentrally located on the bridge M3.

Toward the right .of the bridge H3 the ,bottomof therecever has asubstantially rectangular recess |15, which has inwardly extendingtapered anges |Il adjacent `the aperture ||I for guiding ,the shell intothe barrel. The flanges II'I are close enough together so that when theshell reaches the position of Figure 20 Yit is guided above the flangesI il, but when the ,shell isin the position of the top shell, in Figurer1,2, the narrower part of .the shell may pass between the flanges IIT.

Rearwardly of the bridge H3 .the bottom of the receiver, Figure 15, hasan elongated rectangular aperture H8 which is open at .the rear end,presenting `two rearwardly extending leg portions of the walls HB3, |69.Looking at 4these walls in side elevation, Figure .4, the Wall |119 isformed with a half-cylindrical bearing surface H9 that is Yadapted toengage a complementary forwardly facing half-cylindrical .trunnion ange.|2ilthat is carried by the reaction plate |2.| xedly mounted on thestock-ill.

Below the rearwardly extending tongue .|22 of ethe receiver wall |09,which tongue has the groove IIS, the wall |09 is formed with arectangular groove |23, and the tongue IM which remains below the groove|23 is reduced in thickness, making a thinner wall so that a hook |25-ofthe hammer housing |25 may be mounted with the forward end of the hook|25 inthe groove |23, and the upwardly extending portion of the hookv.|25 outside of the thin part |24 of yeach receiver wall I 08, |89.Thus the -rear end -of the hammer housing has its hook |25 mounted inthe groove |23 and lateral movement of the hammer housing is preventedby the hooks |25 vbeing outside the thin wall portion or tongue I 24. v

'I'.o further explain the function of the bridge |I3 at this time, thehammer housing is associated with the lock housing |27, Figure 22, andwhen assembled has a forwardly extending supporting `flange |28, Figure22, which rests upon the yreceiver bridge H3.

The side walls or legs Iil, |09 of the receiver may have any suitableexterior shape but are vmade thicker toward the forward end -of thereceiver as, for example,v they are thickest at |29 outside the.aperture Ill. They are slightly thinner at It@ `on either side of theaperture LIB, but at the rear end on both sides of `the'open .apertureIIii is vthe thinnest portion |3I of these legs or sidewalls |18, 10,9.

.It shouldbe understoodthat the present Vdrawings `.are made .from .ahand-madegun, the Darts of which were necessarily made out of softsteel, and in order to make them strong enough they had to be madeheavier and thicker than they would be made when made of tempered steel.Thus the parts of the gun may be made smaller and lighter when made oftempered steel than the proportions which are shown in the drawings.

The inner sides of the walls or legs |08, |09 are formed with aninwardly extending rib |32, the top of which rib forms, Figure 10, a bedor guide |33 for the breech block, and this top rib surface |33 extendssubstantially from end to end of the side walls |08, |09 terminating atthe rectangular aperture Figure 20. In other words, the walls |00, |09are thicker at the bottom, providing a flat guide surface |33 insideeach wall, this guide surface being flush with the top of the bridge||3, Figure 9.

Above the bridge ||3, Figure 12, each side wall |08, |09 is formed witha partially cylindrical groove or bearing |34, and this bearing |34faces upward and slightly forward providing a retaining hook formation|35 on its rear wall for engaging the trunnions of the toggle link |36,by means of which the rear end of the barrel is secured to the stock,Figure 32.

The tilting of the half-bearing surfaces |35, Figure 12, forward as wellas upward, tends to retain the trunnions of the toggle link |36 in thesebearings when the toggle link is lying flush with the top of thereceiver and holding the receiver and barrel to the stock.

Referring to Figure 12 again, to the right of bearing groove |34 eachwall |08, |09 is thickened at the beveled surface |31, and formed with adownwardly facing guide surface |30 on an inwardly extending rib |39 forserving as an upper guide for the breech block assembly 43, as shown inFigure 8.

Figure 12 shows a section in which the rear of the breech block assembly43 has its parts provided with laterally projecting guide forma tions346 sliding in the grooves that are formed between the surfaces |33 and|38 of the receiver walls |00, |09. Thus at the forward position of thebreech block assembly 43, Figure l0, the breech block is guided byhaving its parts 346 sliding in the groove |4|, but the front (right)end of the breech block is then above rectangular aperture I, and movesdown into said aperture.

The lower rib |32, Figure 12, terminates in forwardly facing shoulders|42, Figure 20, just forward of the inwardly extending flanges ||1 inthe aperture and the shoulders |42 are the locking lugs by means ofwhich the breech block assembly is locked against rearward movement.

rIhe breech block assembly includes two parts pivotally mounted uponeach other, the forward part having a rearwardly facing shoulder |43,Figure 12, which moves down in front of the breech block locking lug orshoulder |42 when the block is in position against the cartridge whichhas been suitably seated in the cartridge housing 96.

Suitable means are provided for holding the parts in this position sothat the reaction of the shell is taken by the rearwardly facingshoulders |43 against the forwardly facing shoulders |42 on thereceiver.

The receiver also carries at its forward end, Figure 20, a dependingbearing lug |44 for piv- Otally supporting the trunnion |45 in a bore|46, this trunnion being the pivotal support for an operating rod latch|41.

The operating rod latchl The operating rod latch |41 is shown inperspective at the upper left of Figure 21. This latch comprises anelongated metal bar, having an upwardly extending integral lug |50 forsupporting the transversely cylindrical portion |45. This trunnion |45is pivoted in the lug |44 at the forward wall ||0 of the receiver. Theoperating rod latch |41 has a rearwardly extending portion |49, Figure21, which terminates in a vertically extending at flange |5| and alaterally extending finger |52.

The finger |52 may be seen in Figure 20, and it extends over into thereceiver space ||6 in position to be engaged by the uppermost shell inthe magazine, so that the uppermost shell actuates the operating rodlatch |41 and moves it to unlatching position when there are shells inthe magazine.

When there are no shells in the magazine to engage the finger |52 theoperating rod latch |41 remains latched and prevents the breech blockfrom being opened unless it is manually actuated. This manual actuationmay be accomplished by the linger piece |53, which extends downward inFigure 21, but actually extends upward on the side of the barrel justforward of the sight-base 95, as indicated again at |53 in Figure 2a.

The linger piece |53 may be pressed downward when there are no shells inthe magazine to open the breech. It should be noted also that while theleft-hand portion |49 of the action rod latch |41 is located below thereceiver, the vertical flange |5| extends into a special recess |54,Figure 20, in the inside of the side wall |09, bringing the fingerupward into proper position to be engaged by a cartridge in themagazine.

The action rod latch |41 is urged clockwise in Figure 2l by a spring|55, Figure 21, the straight end |56 of which extends into an aperture|51 in the latch. The bent end |58 of this spring is socketed in a hole|59 in the bottom surface ||2 of the wall |09. The right end of theaction rod latch |41 requires special attention.

The right end portion |48 of the operating rod latch |41 not only hasthe finger |53, but at its extreme end a finger |60 extending upward inFigure 2l but downward on the gun. The finger |60 supports a laterallyextending latching shoulder |69, the purpose of which will be laterdescribed. It also has a laterally extending flange 16| and the upwardlyextending ange |62. The upwardly extending flange |62 carries anotherlaterally extending flange |63, which has a downwardly extending ange|64, Figure 21,

The operating rod |65 is shown at the lower right of Figure 21, and itis intended to connect together the breech block assembly and mainspring housing |66 at the time when the main spring is to open thebreech.

We now refer to the right end of the operating rod |65, which has areduced square portion |51 terminating at a shoulder |60. The horizontalflange |63 on the operating rod latch |41 engages the shoulder |58 onthe operating rod |65 (Fig. 2l) whenever this operating rod is to belatched to hold the breech block open. The result is that the operatingrod, which is connected to the breech block, locks the breech block openwhenever the operating rod latch |41 is urged by its lly spring |55.into: engagement withthe 'shoulder |68.

The rearward shoulder on slot 21E of action rod |55 engages` it?,` tolatch the breech block closed unless it is opened manually or by firing.There mustbe a shell ready inthe magazine engaging the finger |52 ofVthe operating rod latch |41 (Fig. 21) to move it against its spring sothat flange it is out of the way of shoulder |68. The resultis that onemay press the finger piecei toV release theoperating rod, and thus topermit one to close the breech block; but the breech block isautomatically unlocked when there isa shell in the magazine.

Theoperating rod latch |131 is also adapted to latch the housingzof thespring it againstlongi tudinal movement. The springliousingr it is shownright side upward; but in'. assembly the. operating rod latch i'll isinverted, andthe inwardly extending shoulder' F59 on the, action rodlatchy IM is in position toerigage shoulder |51 @fion thezspring housingIlt to prevent the spring house ing from moving longitudinally, unlessthe. latch- 1 |41.' is actuated manually at |53 or automatically by acartridge at |52.

Sccurement of the. rear endof barrel to. stock Referringv to Fig. 33 thetoggle link. i3d comprises a transverse yoke |1'I, which carries apairof. parallel legs |12, |13 of rectangular crossr sec-- tion.y The yolae|1| is generally triangular in cross section, but has its apex lillslightly curved, and its base or. opposite forward. edge partiallycylindrical, as at ile'.

The cylindrical parts projectlaterally be.- yond the legs |12, |13, andconstitute trunnions for engagement with the partially cylindricalbearing grooves |16, Figure 32, on the forwardlyv extending pivotviianges |`|1` of' the reaction plate |21. These flanges |11 arev spacedsufficiently for the legs |12, |13'to be received between them with thepartial trunnions |15" lpivoted in the grooves or. bearings |15'.

The reaction plate |2| engages a. plane surface |18. at the rear endofthe recess inthe'. stoclr,A

whichis provided for receiving thebarrel. Eteactionplate |2| has athrough bore |19 for passing a screw bolt |85, by means of which it isanchored to a tang |3'l having athreadedbore |82..

Thetang |8| is carried by. an anchor plate |83, which `is located in arectangular recess IM in the topof. the stockimmediately behindtheireaction.

plate. |2I. The anchor plate is curved com.- plernentarily to the top ofthestock at, the pistol grip, and is flush with the top of, the. stock.'

Anchor plate |83 carries the depending thickl tang ||l|, of rectangularcross-section,v which is located in a downwardly extending rectangularrecess |85 in the pistol grip. The recess |85 is located well behind theplane surface |18 which' behind the action plate edge-|81 and in frontof' the anchor plate |331. Recess |38, Figure 32, al-

lows space' for the pivotal movementfofthe lowerfrontv slots |951 in-thecover extend backvvardly.l

rear.v edge |39, Figure 4, oit-hel cover |90. (Figure- 4) which enclosesthe open part of the receiver behind the breech block assembly t3.

The toggle link Hitl has each of its legs provided-` at their forwardends with a laterally projecting cylindrical trunnion ISH, |32. Thesetrunnions |92 are adapted to bereceived in theA partially;v

cylindrical recess |34 in the top of the sidewalls H18, |89 ofthereceiver.

Thefrear curvedsurface ist of each trunnion` is. adapted to. be'caughtandfretained below'v theV forwardly projecting portion |35, yin thebearing grooves IM. The two legs |`12 I 13 extendparallel" to, theinside top wall of.v thereceiver whichthey` engage, and these. legs|12*7 |13 form atop guide:

surface opposite to the' bed. |33, Figure 12, and. a continuation of.thedownwardly facingaguide surfacesA |38 for' guiding the laterallyprojecting; parts of the breechblock assembly.

The togglelink |35 preferably hasitstrunnions ISI, |92 lprovided withlforwardly extending rea taining` flanges: |394, .for engaging on! theoutside:

of the receiver walls: whenth'e; trunnions. arci in'.

the recessl 34. These flanges-guidethe.- legsi'nto.' proper positionwhen thek parts are being, assembled, as shown in Eigure 32.

Each trunnion. |9|:, |92 is.' preferably provided'. with .anxintegralaxially proie ctin'g pin. wel These pins are utilized in securing thecover in', place; and may be seen inFigurefla-atzthe top.l leftten'fgaging in a. longitudinallyl extending' slot;y |36'v in. each' ofthesidesiof the coverfatfitsforwardedge.

The cover |95 preferablyl comprises a sheet metal. stamping` whichmay'bemade or. suitable steel, andV ity has: ay cylindricallyf cumze'd.topwall` and a. pair: of.: parallel depending side walls the covermay'extend' from thearece'ss |38 (lige ure 2). to a. point". where itioverlaps theY breech block assembly, Figure 4. Its depending walls eX:-ltend downwardly far enough toloverlaptheside walls |03, |09ofthereceiver.

|99; and. a at attaching flange 203' depending' therefrom, and providedwith a` rectangular aperture 20|. The rectangular aperture- 20| is'adapted to receive anv upwardly and' forwardly curved retaining finger2R32, carriedfbythe'anchor" plate |83, Figure 4' and Figure 32'.

Referring to Figure la, it'fwill'be' seen that'th'e or to the'fleftofthe pins-r |555 on toggle link |36.

Atttheysame tiinethe cover; Figure c, has' itsf aperture 20|aboutthenger 2&2 of the anchor'- plate |83'.

The mode 'ofassernbly-ofthe cover is as'follows:v

The cover' has its forward end depresseds and slots |96 placed aboutpins |95. The coverv ISU- isthen slid forward until pins" Iil hit thebase offslots |35, and at' thistirnethe rear attaching y flange 2861 of.the cover clearslthe front" end ofpointed' out that.' the#receiver'walls terminate in' bearingl grooves I |'9fat 'thetop'offl'igure 4: Also' the reaction plate flanges il? have theforwardly extending partially cylindrical bearing formations |22, whichengage in the grooves H9 of the receiver. Figure 4.

The method of securement and assembly of the rea-,f end or" the barrelwith the stock is as follows:

The barrel may be held in diagonal position above the stock, with therear end of the receiver below the trunnion formations |26, as shown inFigure 22. The toggle link is rst inserted in front of the nger 222 insuch manner that its trunnions ll (Figure 32) engage in the bearinggrooves ilf of the reaction plate flanges |11.

The legs or the toggle link |36 are then pressed downward until thefront trunnions ii, |22 move into the grooves |32 in front of theretaining shoulder |35. The barrel may then be lifted at its muzzle enduntil the bearing grooves H9, in the rear end or the receiver, can bebrought up into position to receive the trunnion flanges |20 (Figure 32)on the edge of the flanges I'H.

At this time trunnion flange |22 presses forwardly in groove H2, andtrunnion |75 on the toggle link is pulled forwardly in groove |76, andtrunnions iSi, |22 pulled backwardly in groove |32 on the barrelassembly.

As the barrel is pivoted downward into its groove in the stock, thisrelation is maintained the length of the toggle link is such that whenthe barrel reaches horizontal position the toggle link pulls the barrelassembly backward tightly against the trunnions |22, carried by iiangesill( or" the reaction plate |2 l.

ln some embodiments ol the invention the toggle link |36 may have itspivotal axes so arranged with respect to the axis of the bearing |29that the axis of bearing i6 is above the axes of bearings |76 and |24 atthis time, and this will lock the toggle link with the barrel inhorizontal secured position.

However, it is necessary to provide securement for the front end of thebarrel. and when the iront end is secured to the stock this effectivelyholds the toggle link at the rear end in such position that the rear endis positively secured until the front end is released.

Securement of barrel assembly at front end of stock The barrel d2(Figure 2b) may be provided on its upper side, rearwardly of the frontend 223 of stock 4|, with a welded upwardly projecting rib or lug 262,Figure 26, which may be rectangular in plan and adapted to be receivedin a complementary slot 265 in the front securing band 266. The securingband 226 is shown in greater detail in Figures 24 to 3l.

Referring to this band member in Figures 26 and 27, the securing band266 comprises a metal member, the upper part 20'! of which is partiallycylindrical and formed with a cylindrical bore 268 extending over morethan half the circumference of the barrel L32.

The lower part of the band member 266 has a pair of thick depending sidewalls 269, 220. and a flat bottom wall 2| i, forming a lower rectangularor box-like portion indicated in its entirety at 2 l2. The rectangularlower portion 232 of the band member 266 is adapted to be received in acomplementary recess 2i3, in the forward part of the stock 2|, and therectangular recess 2 I3 is a part of the continuous groove or recess 2|3which extends longitudinally of the stock, and is open at the upper sideof the stock.

Adjacent the band member 266 the stock is also formed with a smallerrectangular recess 2M, Figure 26, and with a through aperture 2I5 forsecuring devices that cooperate with the band 206.

The cylindrical portion 207 extends about the barrel 42, and is pulledbackwardly on the barrel until the lug 264 is seated in the groove 205.This prevents the band member 206 from rotating on the barrel and holdsit in position depending from the barrel.

Band member 266 also provides a support for a front main spring guidebracket 2|6, Figure 24, which also serves as a latching member. Thisguide bracket 2|6 has a rectangular body 2H (Figure 26) which nts in acomplementary rectangular aperture 218 in the depending box-like portion2 2 of the band member 266. It also has a cylindrical bore 2|9, whichreceives the front end of the tubular spring guide 222 for the mainspring 22|, supporting this tubular guide 220 and parallel to it inFigure 24.

The rectangular aperture 2|8 (Figure 26) is also provided at each of itssides with shallow rectangular slots or grooves 222, Figure 26, forslidably supporting the two legs 223 of the main spring frame, indicatedin its entirety by the numeral |66, Figure 26, and seen in perspectivein Figure 21.

The band member 206 and the body 2 II of the bracket 2 6 act as guidesfor supporting the main spring frame |66 for its sliding movement. Thebracket 2|@ (Figure 24.) is also provided with a laterally tapereddepending ilange 2213, having a forwardly extending keeper lug 225 forsecuring the barrel to the stock, and a forwardly extending retainingbar 226 for securing the bracket 2 6 to the band 22E.

The retaining bar 226 is rectangular in crosssection and long enough toproject from the forward end 263 of the stock. The projecting end 221 ofthis retaining bar 226 serves as a manual actuating member, by means ofwhich the bracket 2I6 may be reciprocated against the spring 22| toeffect a release, as will be presently described.

The band member 206 has its lower rectangular body portion 2|2 providedwith a pair of rectangular stirrups 228, Figure 24, Figure 26, thesestirrups having rectangular aligned apertures 229 for slidablysupporting the retaining bar 22?. The stirrups 222 are located forwardlyof the depending part 22d of the bracket 2|6 in a suitable recess in thestock.

The keeper lug 226 extends forwardly from the depending portion 22d ofbracket 2|6, and is tapered toward its end so that it may have a wedgingaction in connection with the stirrup 232 of the front anchor plate 23Figure 26. This front anchor plate 23| has a flat body flange 232 whichmay be rectangular in shape, and substantially as wide as the stock atthis point.

The flat body 232 has an inwardly projecting rectangular stirrup 232,with a rectangular aperture 233, Figure 26, for receiving the wedgingkeeper lug 225. The lower side of the keeper lug 225, Figure 26 andFigure 24, has a clearance with respect to the body 232 of the frontanchor plate 23|, but the upper side 2313 of the keeper lug 225 wedgesagainst the top side of the rectangular aperture 233, and draws theplate 23| upward (Figure 24) at the same time it draws the band member266 and barrel d2 downward.

Thus the keeper lug 225, when urged toward the right, pulls the barreltightly against the stock, and one end of the main spring 22| is seatedagainst the left side 22d of the bracket

